Bio - The fight-or-flight response Flashcards
What is the response to a threatening or stressful situation known as?
The fight-or-flight response.
What are some reactions of the body caused by the fight or flight response?
Faster heartbeat, breathing rate increases, muscles tense.
When an individual is faced with a threat, what area of the brain becomes mobilised?
The amygdala.
When does the amygdala become mobilised?
When an individual is faced with a threat.
What is the fight-or-flight response to?
Stress.
What does the amygdala do?
Associates sensory signals (what we see, hear or smell) with emotions associated with fight or flight, such as fear or anger.
It then sends a distress signal to the hypothalamus, which functions like a command centre in the brain, communicating with the rest of the body through the sympathetic nervous system.
What systems does the body’s response to stressors involve?
One for acute (i.e. sudden) stressors such as personal attack.
One for chronic (i.e. ongoing) stressors such as a stressful job.
When the sympathetic nervous system (SNS) is triggered in the response to acute stressors, what does it do?
Begins the process of preparing the body for the rapid action necessary for fight or flight.
The SNS sends a signal through to the adrenal medulla, which responds by releasing adrenaline into the bloodstream.
What sends the signal to the adrenal medulla to release adrenaline in the response to acute stressors?
The SNS.
What physiological changes does adrenaline cause as it circulates through the body?
Heart beats faster, pushing blood to the muscles, heart and other vital organs, and blood pressure increases. Breathing becomes more rapid in order to take in as much oxygen as possible with each breath.
Adrenaline also triggers the release of blood sugar (glucose) and fats, which flood into the bloodstream, supplying energy to parts of the body associated with the fight or flight response.
What system is activated once the stressors have passed in the response to acute stressors?
Parasympathetic nervous system.
What does the parasympathetic system do?
Slows down the heartbeat again and reduces blood pressure. Digestion (which was inhibited by the SNS) begins again.
What does the HPA axis consist of?
The hypothalamus, pituitary gland and the adrenal gland.
What stress response is triggered if the brain continues to perceive something as threatening?
Response to chronic stressors.
When is the response to chronic stressors activated?
If the brain continues to perceive something as threatening.
